Transmission apparatus, transmission method, reception apparatus, and reception method

ABSTRACT

Reception-side processing performed in a case where transmission of standard dynamic range video data and transmission of high dynamic range video data coexist in a time sequence is simplified. 
     SDR transmission video data is converted into SDR transmission video data through dynamic range conversion. The SDR transmission video data is the one obtained by performing, on SDR video data, photoelectric conversion in accordance with an SDR photoelectric conversion characteristic. In this case, the conversion is performed on the basis of conversion information for converting a value of conversion data in accordance with the SDR photoelectric conversion characteristic into a value of conversion data in accordance with an HDR photoelectric conversion characteristic. A video stream is obtained by performing encoding processing on HDR transmission video data. A container having a predetermined format and including this video stream is transmitted.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/544,285, filed on Jul. 18, 2017, which is a U.S. National Phase ofInternational Patent Application No. PCT/JP2016/053858 filed on Feb. 9,2016, which claims priority benefit of Japanese Patent Application No.JP 2015-029106 filed in the Japan Patent Office on Feb. 17, 2015. Eachof the above-referenced applications are incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present technology relates to a transmission apparatus, atransmission method, a reception apparatus, and a reception method, andparticularly, to a transmission apparatus or the like that transmitsstandard dynamic range video data.

BACKGROUND ART

Conventionally, it has been considered to transmit transmission videodata obtained by applying high dynamic range photoelectric conversion tohigh dynamic range video data. Hereinafter, a high dynamic range isappropriately referred to as “HDR”. For example, there is a descriptionabout an HDR photoelectric conversion characteristic (new gammacharacteristic) in Non-Patent Document 1. The HDR photoelectricconversion characteristic includes a region compatible with aconventional photoelectric conversion characteristic (gammacharacteristic), taking into account reception by a conventionalreceiver.

CITATION LIST Non-Patent Document

-   Non-Patent Document 1: Tim Borer, “Non-Linear Opto-Electrical    Transfer Functions for High Dynamic Range Television”, Research &    Development White Paper WHP 283, July 2014

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

An object of the present technology is to simplify reception-sideprocessing performed in a case where transmission of standard dynamicrange video data and transmission of high dynamic range video data areperformed by a single transmission method.

Solutions to Problems

A concept of the present technology lies in a transmission apparatusincluding:

a dynamic range conversion unit configured to obtain high dynamic rangetransmission video data by performing dynamic range conversion onstandard dynamic range transmission video data on the basis ofconversion information for converting a value of conversion data inaccordance with a standard dynamic range photoelectric conversioncharacteristic into a value of conversion data in accordance with a highdynamic range photoelectric conversion characteristic, the standarddynamic range transmission video data being obtained by performing, onstandard dynamic range video data, photoelectric conversion inaccordance with the standard dynamic range photoelectric conversioncharacteristic;

an encoding unit configured to obtain a video stream by performingencoding processing on the high dynamic range transmission video data;and

a transmission unit configured to transmit a container having apredetermined format and including the video stream.

According to the present technology, the dynamic range conversion unitcan obtain the high dynamic range transmission video data by performingthe dynamic range conversion on the standard dynamic range transmissionvideo data obtained by performing, on the standard dynamic range videodata, the photoelectric conversion in accordance with the standarddynamic range photoelectric conversion characteristic. In such a case,the conversion is performed on the basis of the conversion informationfor converting the value of the conversion data in accordance with thestandard dynamic range photoelectric conversion characteristic into thevalue of the conversion data in accordance with the high dynamic rangephotoelectric conversion characteristic. For example, the conversioninformation may be of a conversion coefficient or a conversion table.

The encoding unit can obtain the video stream by performing the encodingprocessing on the high dynamic range transmission video data. Thetransmission unit transmits the container having the predeterminedformat and including this video stream. For example, the container maybe MP4 used for the Internet distribution or the like, a transportstream (MPEG-2 TS) adopted by a digital broadcasting standard, or acontainer in any other format.

According to the present technology as described above, the standarddynamic range transmission video data is transmitted after beingconverted into the high dynamic range transmission video data. Even whentransmitting the standard dynamic range video data, therefore, thereception side can perform similar processing to that in transmission ofhigh dynamic range video data. This makes it possible to simplify thereception-side processing performed in a case where transmission of thestandard dynamic range video data and transmission of the high dynamicrange video data coexist in a time sequence.

Note that according to the present technology, for example, aninformation insertion unit may be further included. The informationinsertion unit inserts, into the video stream and/or the container, theconversion information for converting the value of the conversion datain accordance with the standard dynamic range photoelectric conversioncharacteristic into the value of the conversion data in accordance withthe high dynamic range photoelectric conversion characteristic. In acase where the conversion information is inserted as described above,the reception side can easily perform processing for converting the highdynamic range transmission video data into the standard dynamic rangetransmission video data with this conversion information and displayinga standard dynamic range image.

Furthermore, according to the present technology, for example, theinformation insertion unit may further insert, into the container,information indicating that the video stream supports a high dynamicrange. This information allows the reception side to easily recognizethat the video stream supports the high dynamic range.

Furthermore, according to the present technology, for example, theinformation insertion unit may further insert, into the container,information indicating a high dynamic range electro-optical conversioncharacteristic corresponding to the high dynamic range photoelectricconversion characteristic. This information allows the reception side toeasily recognize the high dynamic range electro-optical conversioncharacteristic corresponding to the high dynamic range photoelectricconversion characteristic.

Furthermore, according to the present technology, for example, theinformation insertion unit may further insert, into the container,information indicating that original video data is the standard dynamicrange video data. This information allows the reception side to easilyrecognize that the original video data is the standard dynamic rangevideo data.

Furthermore, another concept of the present technology lies in areception apparatus including:

a reception unit configured to receive a container having apredetermined format and including a video stream obtained by encodinghigh dynamic range transmission video data;

a decoding unit configured to obtain the high dynamic range transmissionvideo data by performing decoding processing on the video stream;

a dynamic range conversion unit configured to obtain standard dynamicrange transmission video data by performing dynamic range conversion onthe high dynamic range transmission video data obtained by the decodingunit; and

an electro-optical conversion unit configured to obtain display standarddynamic range video data by performing, on the standard dynamic rangetransmission video data, electro-optical conversion in accordance with astandard dynamic range electro-optical conversion characteristic, thestandard dynamic range transmission video data being obtained by thedynamic range conversion unit.

According to the present technology, the reception unit receives thecontainer having the predetermined format and including the video streamobtained by encoding the high dynamic range transmission video data. Thedecoding unit can obtain the high dynamic range transmission video databy performing the decoding processing on the video stream.

The dynamic range conversion unit can obtain the standard dynamic rangetransmission video data by performing the dynamic range conversion onthe high dynamic range transmission video data obtained by the decodingunit. Then, the electro-optical conversion unit can obtain the displaystandard dynamic range video data by performing, on the standard dynamicrange transmission video data, the electro-optical conversion inaccordance with the standard dynamic range electro-optical conversioncharacteristic.

According to the present technology as described above, the standarddynamic range transmission video data is obtained by performing thedynamic range conversion on the high dynamic range transmission videodata obtained by the decoding processing. Accordingly, even in the caseof being transmitted as the high dynamic range transmission video data,it is possible to display a standard dynamic range image satisfactorily.

Note that according to the present technology, for example, the highdynamic range transmission video data obtained by the decoding unit maybe obtained by performing dynamic range conversion processing on thestandard dynamic range transmission video data on the basis ofconversion information for converting a value of conversion data inaccordance with a standard dynamic range photoelectric conversioncharacteristic into a value of conversion data in accordance with a highdynamic range photoelectric conversion characteristic. The standarddynamic range transmission video data is obtained by performing, onstandard dynamic range video data, photoelectric conversion inaccordance with the standard dynamic range photoelectric conversioncharacteristic.

Furthermore, according to the present technology, for example, theconversion information may be inserted into the video stream and/or thecontainer. A conversion information extraction unit to extract theconversion information from the video stream and/or the container may befurther included. The dynamic range conversion unit may perform dynamicrange conversion on the basis of the conversion information extracted bythe conversion information extraction unit.

EFFECTS OF THE INVENTION

According to the present technology, it is possible to simplifyreception-side processing performed in a case where transmission ofstandard dynamic range video data and transmission of high dynamic rangevideo data coexist in a time sequence. Note that the effects describedin this specification are merely examples and not limited thereto, andadditional effects may also be included.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1(a) and 1(b) are block diagrams illustrating exemplaryconfigurations of an MPEG-DASH-based stream distribution system.

FIGS. 2(a) to 2(e) are diagrams illustrating an example of arelationship between each of structures hierarchically arranged in anMPD file.

FIG. 3 is a block diagram illustrating an exemplary configuration of atransmission and reception system as an embodiment.

FIG. 4 is a block diagram illustrating an exemplary configuration of aservice transmission system.

FIG. 5 is a diagram for describing an operation of a dynamic rangeconversion unit in the service transmission system.

FIG. 6 is a diagram illustrating an access unit at the head of a GOP ina case where an encoding method is HEVC.

FIG. 7 is a diagram illustrating an exemplary structure of a dynamicrange conversion SEI message.

FIG. 8 is a diagram illustrating contents of main information in theexemplary structure of the dynamic range conversion SEI message.

FIG. 9 is a diagram for describing a media file entity for anon-fragmented MP4 (Non-Fragmented MP4) case (VOD service).

FIG. 10 is a diagram for describing a media file entity for a fragmentedMP4 (Fragmented MP4) case (multicast service).

FIG. 11 is a diagram for describing a media file entity for a fragmentedMP4 (Fragmented MP4) case (broadcasting).

FIG. 12 is a diagram illustrating an exemplary description of the MPDfile.

FIG. 13 is a diagram illustrating “Value” semantics of“SupplementaryDescriptor”.

FIG. 14 is a block section illustrating an exemplary configuration of aservice receiver.

FIG. 15 is a diagram for describing details of dynamic range inverseconversion in a case where original video data of a current stream isSDR video data.

FIG. 16 is a diagram for describing details of dynamic range inverseconversion in a case where original video data of a current stream isHDR video data.

FIG. 17 is a diagram illustrating an exemplary structure of a dynamicrange conversion descriptor.

FIG. 18 is a diagram illustrating contents of main information in theexemplary structure of the dynamic range conversion descriptor.

FIG. 19 is a diagram illustrating an exemplary configuration of atransport stream.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a mode for carrying out the invention (hereinafter referredto as “embodiment”) will be described. Note that the description will begiven in the following order.

1. Embodiment

2. Modification

1. Embodiment [Overview of the MPEG-DASH-Based Stream DistributionSystem]

First, an overview of an MPEG-DASH-based stream distribution system towhich the present technology can be applied will be described.

FIG. 1(a) illustrates an exemplary configuration of an MPEG-DASH-basedstream distribution system 30A. In this exemplary configuration, a mediastream and an MPD file are transmitted through a communication networktransmission line (communication transmission line). This streamdistribution system 30A has a configuration in which N number of servicereceivers 33-1, 33-2, . . . , and 33-N are connected to a DASH streamfile server 31 and a DASH MPD server 32 via a content delivery network(CDN) 34.

The DASH stream file server 31 generates a stream segment conforming toDASH specifications (hereinafter, appropriately referred to as a “DASHsegment”) on the basis of media data (video data, audio data, subtitledata, and the like) of a predetermined content, and transmits thesegment in response to an HTTP request from the service receiver. ThisDASH stream file server 31 may be a server dedicated to streaming or mayalso be used as a web (Web) server.

Furthermore, in response to the request for the segment of thepredetermined stream transmitted from the service receiver 33 (33-1,33-2, . . . , and 33-N) via the CDN 34, the DASH stream file server 31transmits the segment of the stream to the receiver, which is therequest source, through the CDN 34. In this case, the service receiver33 makes the request by referring to values of rates described in amedia presentation description (MPD) file and selecting a stream with anoptimal rate according to the condition of a network environment wherethe client is placed.

The DASH MPD server 32 is a server that generates an MPD file forobtaining the DASH segment generated in the DASH stream file server 31.The MPD file is generated on the basis of content metadata transmittedfrom a content management server (not illustrated) and an address (url)of the segment generated in the DASH stream file server 31. Note thatthe DASH stream file server 31 and the DASH MPD server 32 may bephysically an identical server.

The MPD format uses an element called a representation (Representation)for each of the streams such as videos and audio to describe acorresponding attribute. In the MPD file, for example, therepresentation is separated for each of a plurality of video datastreams having different rates to describe their respective rates. Theservice receiver 33 can refer to the values of these rates and select anoptimal stream according to the condition of the network environmentwhere the service receiver 33 is placed, as described above.

FIG. 1(b) illustrates an exemplary configuration of an MPEG-DASH-basedstream distribution system 30B. In this exemplary configuration, a mediastream and an MPD file are transmitted through an RF transmission line(broadcast transmission line). This stream distribution system 30Bincludes a broadcast transmission system 36 to which a DASH stream fileserver 31 and a DASH MPD server 32 are connected, and M number ofservice receivers 35-1, 35-2, . . . , and 35-M.

In the case of this stream distribution system 30B, the broadcasttransmission system 36 transmits a stream segment and an MPD file on abroadcast wave. The stream segment (DASH segment) conforming to the DASHspecifications is generated by the DASH stream file server 31. The MPDfile is generated by the DASH MPD server 32.

FIGS. 2(a) to 2(e) illustrate an example of a relationship between eachof structures hierarchically arranged in the MPD file. As illustrated inFIG. 2(a), there exists a plurality of periods (Period) divided by timeintervals in a media presentation (Media Presentation) as a whole MPDfile. For example, the first period starts from 0 seconds, the nextperiod starts from 100 seconds, and the like.

As illustrated in FIG. 2(b), there exists a plurality of adaptation sets(AdaptationSet) in the period. Each adaptation set depends ondifferences in media types such as videos and audio and differences inlanguages, viewpoints, and the like in the same media type. Asillustrated in FIG. 2(c), there exists a plurality of representations(Representation) in the adaptation set. Each representation depends onstream attributes, for example, differences in rates.

As illustrated in FIG. 2(d), the representation includes segment info(SegmentInfo). As illustrated in FIG. 2(e), there exist aninitialization segment (Initialization Segment) and a plurality of mediasegments (Media Segment) in this segment info. Information for each ofthe segments (Segment) into which the period is further finely dividedis described in the media segments (Media Segment). In the mediasegments, there exist address (url) information and the like to actuallyobtain segment data such as videos and audio.

Note that streams can be freely switched between the plurality ofrepresentations included in the adaptation set. This configurationallows selection of a stream with an optimum rate according to thecondition of the network environment on the reception side, enablingseamless video distribution.

[Exemplary Configuration of the Transmission and Reception System]

FIG. 3 illustrates an exemplary configuration of a transmission andreception system 10 as an embodiment. This transmission and receptionsystem 10 includes a service transmission system 100 and a servicereceiver 200. The service transmission system 100 in this transmissionand reception system 10 corresponds to the DASH stream file server 31and the DASH MPD server 32 in the stream distribution system 30Aillustrated in FIG. 1(a) described above. Furthermore, the servicetransmission system 100 in this transmission and reception system 10corresponds to the DASH stream file server 31, the DASH MPD server 32,and the broadcast transmission system 36 in the stream distributionsystem 30B illustrated in FIG. 1(b) described above.

Furthermore, the service receiver 200 in this transmission and receptionsystem 10 corresponds to the service receiver 33 (33-1, 33-2, . . . ,and 33-N) in the stream distribution system 30A illustrated in FIG. 1(a)described above. Furthermore, the service receiver 200 in thistransmission and reception system 10 corresponds to the service receiver35 (35-1, 35-2, . . . , and 35-M) in the stream distribution system 30Billustrated in FIG. 1(b) described above.

The service transmission system 100 transmits DASH/MP4, that is, an MPDfile as a metafile, as well as MP4 including a media stream (mediasegment) such as a video and audio through the communication networktransmission line (see FIG. 1(a)) or the RF transmission line (see FIG.1(b)).

“Exemplary Configuration of the Service Transmission System”

FIG. 4 illustrates an exemplary configuration of the servicetransmission system 100. This service transmission system 100 includes acontrol unit 101, an HDR photoelectric conversion unit 103, an SDRphotoelectric conversion unit 104, a dynamic range conversion unit 105,a changeover switch 106, an RGB/YCbCr conversion unit 107, a videoencoder 108, a container encoder 109, and a transmission unit 110.

The control unit 101 includes a central processing unit (CPU), andcontrols the operation of each unit of the service transmission system100 on the basis of a control program. The HDR photoelectric conversionunit 103 performs photoelectric conversion by applying an HDRphotoelectric conversion characteristic to a high contrast cameraoutput, that is, high dynamic range (HDR) video data Vh, and obtains HDRtransmission video data. This HDR transmission video data becomes avideo material produced as a video by an HDR OETF.

The SDR photoelectric conversion unit 104 performs photoelectricconversion by applying an SDR photoelectric conversion characteristic toa standard contrast camera output, that is, standard dynamic range (SDR)video data Vs, and obtains SDR transmission video data. This SDRtransmission video data becomes a video material produced as a video byan SDR OETF.

The dynamic range conversion unit 105 obtains HDR transmission videodata by performing dynamic range conversion on the SDR transmissionvideo data. That is, this dynamic range conversion unit 105 converts theSDR transmission video data, which is the video material produced as thevideo by the SDR OETF, into the HDR transmission video data. Here, thedynamic range conversion unit 105 performs the dynamic range conversionon the basis of conversion information. The conversion information isfor converting a value of conversion data in accordance with the SDRphotoelectric conversion characteristic into a value of conversion datain accordance with the HDR photoelectric conversion characteristic. Thisconversion information is given, for example, by the control unit 101.

The dynamic range conversion will be further described with reference toFIG. 5. A solid line a indicates an example of an SDR OETF curveindicating the SDR photoelectric conversion characteristic. A solid lineb indicates an example of an HDR OETF curve indicating the HDRphotoelectric conversion characteristic. The horizontal axis indicatesan input luminance level. P1 indicates an input luminance levelcorresponding to the SDR maximum level. P2 indicates an input luminancelevel corresponding to the HDR maximum level.

Furthermore, the vertical axis indicates a transmission code value or arelative value of a normalized encoding level. A relative maximum levelM indicates the HDR maximum level and the SDR maximum level. A referencelevel G indicates a transmission level of the HDR OETF at the inputluminance level P1 corresponding to the SDR maximum level, which means aso-called white level as a reference. It is indicated that the rangehigher than this level is used for sparkling expression which is uniqueto HDR. A branch level B indicates a level at which the SDR OETF curveand the HDR OETF curve branch and separate from the same locus. Pfindicates an input luminance level corresponding to the branch level.Note that this branch level B can be any value equal to or greater than0.

The SDR transmission video data from the branch level B to the relativemaximum level M is converted into a value of the conversion data inaccordance with the HDR photoelectric conversion characteristic throughthe dynamic range conversion performed by the dynamic range conversionunit 105. In this case, the relative maximum level M which is the SDRmaximum level is made to match the reference level G. Note that theinput data less than the branch level B becomes output data as it is.

Here, the conversion information is given by a conversion table or aconversion coefficient. In a case where the conversion information isgiven by the conversion table, the dynamic range conversion unit 105performs the conversion by referring to this conversion table. Incontrast, in a case where the conversion information is given by theconversion coefficient, the dynamic range conversion unit 105 performsthe conversion by making a calculation using this conversioncoefficient. For example, in a case where the conversion coefficient isC, the input data from the branch level B to the relative maximum levelM is converted using the following equation (1).

Output data=branch level B+(input data−branch level B)*C   (1)

Referring back to FIG. 4, the changeover switch 106 selectively takesout the HDR transmission video data obtained by the HDR photoelectricconversion unit 103 or the HDR transmission video data obtained by thedynamic range conversion unit 105. The RGB/YCbCr conversion unit 107converts the HDR transmission video data taken out by the changeoverswitch 106 from an RGB domain to a YCbCr (luminance and chrominance)domain. In this case, the RGB/YCbCr conversion unit 107 performs theconversion using a conversion equation corresponding to a color space onthe basis of color space information. Note that these color spacedomains are not limited to the RGB domain, and the luminance andchrominance domain is not limited to YCbCr.

The video encoder 108 performs encoding, for example, MPEG4-AVC or HEVCon HDR transmission video data V1 which has been converted into theYCbCr domain by the RGB/YCbCr conversion unit 107, and obtains encodedvideo data. The video encoder 108 then generates a video stream (videoelementary stream) VS including this encoded video data.

At this time, the video encoder 108 inserts meta-information into avideo usability information (VUI) area of an SPS NAL unit of an accessunit (AU). The meta-information indicates that the stream is an HDRstream, and furthermore, an HDR electro-optical conversioncharacteristic and the like. Furthermore, the video encoder 108 insertsa newly defined dynamic range conversion SEI message (Dynamic_range_convSEI message) into “SEIs” part of the access unit (AU). The dynamic rangeconversion SEI message includes the conversion information on thedynamic range conversion described above. FIG. 6 illustrates an accessunit located at the head of a group of pictures (GOP) in a case where anencoding method is HEVC. In the case of the HEVC encoding method, an SEImessage group “Prefix_SEIs” for decoding is arranged before a slice(slices) where pixel data is encoded, and an SEI message group“Suffix_SEIs” for display is arranged after this slice (slices). Asillustrated in the figure, the dynamic range conversion SEI message isarranged as, for example, the SEI message group “Suffix_SEIs”.

FIG. 7 illustrates an exemplary structure (Syntax) of the dynamic rangeconversion SEI message. FIG. 8 illustrates contents (Semantics) of themain information in the exemplary structure. One-bit flag information of“Dynamic_range_conv_cancel_flag” indicates whether a message of“Dynamic_range_conv” is refreshed. “0” indicates that the message of“Dynamic_range_conv” is refreshed. “1” indicates that the message of“Dynamic_range_conv” is not refreshed. That is, the previous message ismaintained as it is.

In a case where “Dynamic_range_conv_cancel_flag” is “0”, the followingfields exist. An 8-bit field of “coded_data_bit_depth” indicates a bitdepth of encoded pixels (bit depth of the transmission code value). A14-bit field of “reference_level” indicates a reference luminance levelvalue, that is, the reference level G (see FIG. 5). One-bit flaginformation of “ratio_conversion_flag” indicates that a simpleconversion is performed, that is, indicating that there exists aconversion coefficient. One-bit flag information of“conversion_table_flag” indicates that a conversion table is used, thatis, indicating that there exists conversion table information. A 16-bitfield of “branch_level” indicates the branch level B (see FIG. 5).

In a case where “ratio_conversion_flag” is “1”, an 8-bit field of“level_conversion_ratio” exists. This field indicates the conversioncoefficient (ratio of level conversion). In a case where“conversion_table_flag” is “1”, an 8-bit field of “table_size” exists.This field indicates the number of inputs in the conversion table. Then,“level_R[i]”, “level_G[i]”, and “level_B[i]” having 16-bit field eachexists for the number of inputs. The “level_R[i]” field indicates avalue after conversion of a red component (Red component). The“level_G[i]” field indicates a value after conversion of a greencomponent (Red component). The “level_B[i]” field indicates a valueafter conversion of a blue component (Red component).

Note that in a case where the bit depth of the encoded pixels is 8 bits,values corresponding to respective values of the input data exist.However, in a case where the bit depth of the encoded pixels is 10 bits,12 bits or the like, only values corresponding to respective values ofhigh-order 8 bits of the input data exist. In this case, when theconversion table is used on the reception side, interpolated values areused for values of the remaining low-order bits.

Referring back to FIGS. 1(a) and 1(b), the container encoder 109generates a container, here MP4, as a distribution stream STM. Thecontainer includes a video stream VS generated by the video encoder 108.Description will be given on a media file entity at a locationdestination indicated by “<baseURL>” for a non-fragmented MP4(Non-Fragmented MP4) case (VOD service).

In this case, it may be defined as “url 1” as illustrated in FIG. 9. Inthis case, an “ftyp” box is arranged first. The “ftyp” is where a filetype is described. Indicated by this “ftyp” box is a non-fragmented MP4file. Subsequently, a “moon” box and an “mdat” box are arranged. The“moon” box includes all the metadata, for example, header information ofa track, meta description of contents of the content, and timeinformation. In the “mdat” box, a SLICE NAL unit is arranged. The SLICENAL unit is the media data body. Note that each NAL unit of an SPS, aVPS, a PPS, and an SEI can also be arranged in this “mdat” box.

Furthermore, each NAL unit of the SPS, the VPS, the PPS, and the SEI isarranged in an “stsd” box under the “moon” box (method 1).Meta-information of a video usability information (VUI) area of the SPSNAL unit indicates, for example, that the stream is an HDR stream.Furthermore, there also exists a NAL unit of the above-described dynamicrange conversion SEI message as an SEI NAL unit. Note that elementsdefined by a “kind” box in the “udta” box under the “moon” box may beused to indicate, for example, that the stream is an HDR stream (method2).

Furthermore, description will be given on a media file entity at alocation destination indicated by “<baseURL>” for a fragmented MP4(Fragmented MP4) case (multicast service).

In this case, it may be defined as “url 2” as illustrated in FIG. 10. Inthis case, an “styp” box is arranged first. The “styp” box is where afile type is described. Subsequently, a “sidx” box is arranged. The“sidx” box is where a segment index is described. After that, apredetermined number of movie fragments (Movie Fragment) are arranged.

Each movie fragment includes a “moon” box, a “moof” box, and an “mdat”box. The “moof” includes fragment control information. The “mdat” boxincludes media data body. The multicast service has to be subjected torandom access. To cope with the random access, it is necessary toarrange the “moon” box in each movie fragment. This configuration willbe similarly applied to the broadcasting case described later. In the“mdat” box, a SLICE NAL unit is arranged. The SLICE NAL unit is themedia data body. Note that each NAL unit of an SPS, a VPS, a PPS, and anSEI can also be arranged in this “mdat” box.

Furthermore, each NAL unit of the SPS, the VPS, the PPS, and the SEI isarranged in an “stsd” box under the “moon” box (method 1).Meta-information of a video usability information (VUI) area of the SPSNAL unit indicates, for example, that the stream is an HDR stream.Furthermore, there also exists a NAL unit of the above-described dynamicrange conversion SEI message as an SEI NAL unit. Note that elementsdefined by a “kind” box in the “udta” box under the “moon” box may beused to indicate, for example, that the stream is an HDR stream (method2).

Furthermore, description will be given on a media file entity for afragmented MP4 (Fragmented MP4) case (broadcasting). In this case, an“styp” box is arranged first as illustrated in FIG. 11. The “styp” boxis where a file type is described. Subsequently, a “sidx” box isarranged. The “sidx” box is where a segment index is described. Afterthat, a predetermined number of combinations of an “MPD” box and a moviefragment (Movie Fragment) are arranged.

An MPD file is arranged in the “MPD” box. Each movie fragment includes a“moon” box, a “moof” box, and an “mdat” box. The “moof” includesfragment control information. The “mdat” box includes media data body.In the “mdat” box, a SLICE NAL unit is arranged. The SLICE NAL unit isthe media data body. Note that each NAL unit of an SPS, a VPS, a PPS,and an SEI can also be arranged in this “mdat” box.

Furthermore, each NAL unit of the SPS, the VPS, the PPS, and the SEI isarranged in an “stsd” box under the “moov” box (method 1).Meta-information of a video usability information (VUI) area of the SPSNAL unit indicates, for example, that the stream is an HDR stream.Furthermore, there also exists a NAL unit of the above-described dynamicrange conversion SEI message as an SEI NAL unit. Note that elementsdefined by a “kind” box in the “udta” box under the “moon” box may beused to indicate, for example, that the stream is an HDR stream (method2).

Note that the MPD file can be considered to include the meta-informationin the above-described VUI area, dynamic conversion information, and thelike. In the MPD file, “schemeIdUri” can be newly defined asbroadcasting or any other applications by “SupplementaryDescriptor”,separately from an existing definition in the conventional standard.

FIG. 12 illustrates an exemplary description of the MPD file. Althoughthe example illustrated herein describes only information on videostreams to simplify the description, information on media streams otherthan the video streams is also described in practice. FIG. 13illustrates “Value” semantics of “SupplementaryDescriptor”.

The description of “<AdaptationSet mimeType=“video/mp4” group=“1”>”indicates that there exists an adaptation set (AdaptationSet) for avideo stream, the video stream is supplied with an MP4 file structure,and a group 1 is allocated. The description of “<SupplementaryDescriptorschemeIdUri=“urn:brdcst:codecType” value=“hevc”/> indicates that thecodec of the video stream is “HEVC”.

The description of <SupplementaryDesctiptorschemeIdUri=“urn:brdcst:video:highdynamicrange” value=“HDR”/> indicatesthat the current stream is an HDR stream. Note that “1” may be describedinstead of “HDR” to indicate that the current stream is an HDR stream.Furthermore, “SDR” or “0” is described to indicate that the currentstream is an HDR stream.

The description of <SupplementaryDesctiptorschemeIdUri=“urn:brdcst:video:transferfunction” value=“EOTFtype”/>indicates an electro-optical conversion characteristic (EOTFcharacteristic). For example, in the case of “BT.709-5 TransferFunction”, “bt709” or “1” is described in the “EOTFtype” part.Furthermore, for example, in the case of “10 bit BT.2020 TransferFunction”, “bt2020” or “14” is described in the “EOTFtype” part.Furthermore, for example, in the case of “SMPTE 2084 Transfer Function”,“st2028” or “16” is described in the “EOTFtype” part.

The description of <SupplementaryDesctiptorschemeIdUri=“urn:brdcst:video:xycolourprimaries” value=“ColorGamut”/>indicates a color space. For example, in the case of “BT.709-5”, “bt709”or “1” is described in the “ColorGamut” part. Furthermore, for example,in the case of “BT.2020”, “bt2020” or “9” is described in the“ColorGamut” part. Furthermore, for example, in the case of “SMPTE 428or XYZ”, “st428” or “10” is described in the “ColorGamut” part.

The description of <SupplementaryDesctiptorschemeIdUri=“urn:brdcst:video:matrixcoefficients” value=“ColorMatrix”/>indicates a color matrix coefficient. For example, in the case of“BT.709-5”, “bt709” or “1” is described in the “ColorMatrix” part.Furthermore, for example, in the case of “BT.2020 non-constantlumiinance”, “bt2020n” or “9” is described in the “ColorMatrix” part.Furthermore, for example, in the case of “SMPTE 2085 or Y′D′zD′x″,“st2085” or “11” is described in the “ColorMatrix” part.

The description of <SupplementaryDesctiptorschemeIdUri=“urn:brdcst:video:referencelevel” value=“RefLevel”/>indicates the reference level G (see FIG. 5). A reference levelspecified with a value of 0 to 100 in a relative range normalized to “1”at maximum is described in the “RefLevel” part. A value obtained bydividing this value by 100 is recognized as a relative reference levelon the reception side. This relative reference level constitutes aconversion coefficient as conversion information for the dynamic rangeconversion.

The description of <SupplementaryDesctiptorschemeIdUri=“urn:brdcst:video:branchlevel” value=“BranchLevel”/>indicates the branch level B(see FIG. 5). A branch level specified witha value of 0 to 100 in a relative range normalized to “1” at maximum isdescribed in the “BranchLevel” part. A value obtained by dividing thisvalue by 100 is recognized as a relative reference level on thereception side.

The description of <SupplementaryDesctiptorschemeIdUri=“urn:brdcst:video:streamdependency” value=“DependType”/>indicates whether the current stream is an independent stream. In thecase of an independent stream, “base” or “0” is described in the“DependType” part. In the case of a dependent stream, “extended” or “1”is described in the “DependType” part.

The description of <SupplementaryDesctiptorschemeIdUri=“urn:brdcst:video:originaldynamicrange” value=“DrangeType”/>indicates whether original video data of the current stream is SDR videodata. In the case of SDR video data, “sdr” is described in the“DrangeType” part. In the case of HDR video data, “hdr” is described inthe “DrangeType” part.

The description of “<Representation id=“1” bandwidth=“20000000”>”indicates that there exists a video stream with a bit rate of 20 Mbps,which includes encoded data of group 1 “group1” as a representationidentified by “Representation id=“1”” in the adaptation set of thegroup 1. Then, the description of“<baseURL>video/jp/20000000.mp4</BaseURL>” indicates that a locationdestination of the video stream is “video/jp/20000000.mp4”.

The exemplary description of the MPD file in FIG. 12 is an example in acase where a dependent stream exists. The description of “<AdaptationSetmimeType=“video/mp4” group=“2”>” indicates that there exists anadaptation set (AdaptationSet) for a video stream, the video stream issupplied with the MP4 file structure, and a group 2 is allocated.Although detailed description is omitted, information similar to that ofthe video stream of the group 1 described above is also described forthe video stream of the group 2.

Note that the elements defined by the “kind” box in the “udta” box underthe “moon” box described above can be, for example, the elementsenclosed by a broken line frame in FIG. 12.

Referring back to FIG. 4, the transmission unit 110 transmits the MP4distribution stream STM, which has been obtained by the containerencoder 109, to the service receiver 200 on a broadcast wave or in anetwork packet.

The operation of the service transmission system 100 illustrated in FIG.4 will be briefly described. HDR video data Vh, which is a high contrastcamera output, is supplied to the HDR photoelectric conversion unit 103.In this HDR photoelectric conversion unit 103, photoelectric conversionis performed on the HDR video data Vh on the basis of an HDRphotoelectric conversion characteristic, and HDR transmission video datais obtained as a video material produced as a video by an HDR OETF.

Furthermore, SDR video data Vs, which is a standard contrast cameraoutput, is supplied to the SDR photoelectric conversion unit 104. Inthis SDR photoelectric conversion unit 104, photoelectric conversion isperformed on the SDR video data Vs on the basis of an SDR photoelectricconversion characteristic, and SDR transmission video data is obtainedas a video material produced as a video by an SDR OETF.

The SDR transmission video data obtained in the SDR photoelectricconversion unit 104 is supplied to the dynamic range conversion unit105. In the dynamic range conversion unit 105, dynamic range conversionis performed on the SDR transmission video data on the basis ofconversion information (conversion table, conversion coefficient)supplied from the control unit 101. The SDR transmission video data isconverted into the HDR transmission video data through this dynamicrange conversion (see FIG. 5).

In the changeover switch 106, the HDR transmission video data obtainedin the HDR photoelectric conversion unit 103 or the HDR transmissionvideo data obtained in the dynamic range conversion unit 105 isselectively taken out under control of the control unit 101. The HDRtransmission video data taken out in this way is converted from the RGBdomain to the YCbCr (luminance and chrominance) domain in the RGB/YCbCrconversion unit 107.

The HDR transmission video data V1 converted into the YCbCr domain issupplied to the video encoder 108. In this video encoder 108, encoding,for example, MPEG4-AVC or HEVC is performed on the HDR transmissionvideo data V1 to obtain encoded video data, through which a video streamVS including this encoded video data is generated.

In the video encoder 108, at this time, meta-information is insertedinto a video usability information (VUI) area of an SPS NAL unit of anaccess unit (AU). The meta-information indicates that the stream is anHDR stream, and furthermore, an HDR electro-optical conversioncharacteristic, and the like. In the video encoder 108, furthermore, anewly defined dynamic range conversion SEI message is inserted into an“SEIs” part of the access unit (AU). The dynamic range conversion SEImessage includes the conversion information (conversion cable,conversion coefficient) on the dynamic range conversion (see FIG. 7).

The video stream VS obtained in the video encoder 108 is supplied to thecontainer encoder 109. In the container encoder 109, MP4 that is acontainer including the video stream VS is generated as a distributionstream STM. At this time, meta-information is inserted into MP4, forexample, under the “moon” box. The meta-information indicates, forexample, that the stream is an HDR stream.

This distribution stream STM is transmitted by the transmission unit 110to the service receiver 200 on a broadcast wave or in a network packet.

“Exemplary Configuration of the Service Receiver”

FIG. 14 illustrates an exemplary configuration of the service receiver200. This service receiver 200 includes a control unit 201, a receptionunit 202, a container decoder 203, a video decoder 204, a YCbCr/RGBconversion unit 205, a changeover switch 206, an HDR electro-opticalconversion unit 207, a dynamic range inverse conversion unit 208, and anSDR electro-optical conversion unit 209.

The control unit 201 includes a central processing unit (CPU), andcontrols the operation of each unit of the service receiver 200 on thebasis of a control program. The reception unit 202 receives an MP4distribution stream STM transmitted from the service transmission system100 on a broadcast wave or in a network packet. The container decoder203 extracts a video stream VS from the MP4. Furthermore, the containerdecoder 203 extracts meta-information from the MP4 and transmits themeta-information to the control unit 201. The control unit 201recognizes from this meta-information that the stream is an HDR stream,as well as HDR electro-optical conversion characteristic information,original video data information, and the like.

The video decoder 204 performs decoding processing on the video streamVS extracted by the container decoder 203, and obtains HDR transmissionvideo data V1. Furthermore, parameter sets and an SEI message insertedinto each access unit constituting the video stream VS are extracted andtransmitted to the control unit 201 by the video decoder 204.

The control unit 201 recognizes from the meta-information in a VUI areaof an SPS NAL unit that the stream is an HDR stream, as well as the HDRelectro-optical conversion characteristic information, and the like.Furthermore, the control unit 201 recognizes dynamic range conversioninformation (conversion table, conversion coefficient) from a dynamicrange conversion SEI message.

The YCbCr/RGB conversion unit 205 converts the HDR transmission videodata V1, which has been obtained by the video decoder 204, from theYCbCr (luminance and chrominance) domain to the RGB domain. Thechangeover switch 206 transmits the HDR transmission video data V1,which has been converted into the RGB domain, to the HDR electro-opticalconversion unit 207 or the dynamic range inverse conversion unit 208under control of the control unit 201.

In this case, in a case where a display monitor (not illustrated)supports HDR, the changeover switch 206 transmits the HDR transmissionvideo data to the HDR electro-optical conversion unit 207. On the otherhand, in a case where a display monitor supports SDR, the changeoverswitch 206 transmits the HDR transmission video data to the dynamicrange inverse conversion unit 208.

The control unit 201 sets the HDR electro-optical conversioncharacteristic in the HDR photoelectric conversion unit 207. The HDRelectro-optical conversion characteristic is the one recognized from themeta-information, that is, the HDR electro-optical conversioncharacteristic corresponding to an HDR photoelectric conversioncharacteristic used on the transmission side. The HDR photoelectricconversion unit 207 obtains display video data Vhd for displaying an HDRimage by applying the HDR electro-optical conversion characteristic tothe HDR transmission video data V1 taken out by the changeover switch206.

The control unit 201 gives the dynamic range inverse conversion unit208, for example, the dynamic range conversion information (conversiontable, conversion coefficient) recognized from the dynamic rangeconversion SEI message. The dynamic range inverse conversion unit 208performs, on the basis of this conversion information, dynamic rangeinverse conversion on the HDR transmission video data V1 which has beentaken out by the changeover switch 206, and obtains SDR transmissionvideo data.

The details of the dynamic range inverse conversion will be describedwith reference to FIG. 15. This is a case where original video data ofthe current stream is SDR video data. The vertical axis indicates anoutput luminance level, which corresponds to the horizontal axis in FIG.5. Furthermore, the horizontal axis indicates a transmission code value,which corresponds to the vertical axis in FIG. 5. A solid line a is anSDR EOTF curve indicating an SDR electro-optical conversioncharacteristic. This SDR EOTF curve corresponds to the SDR OETF curveindicated by the solid line a in FIG. 5. A solid line b is an HDR EOTFcurve indicating an HDR electro-optical conversion characteristic. ThisHDR EOTF curve corresponds to the HDR OETF curve indicated by the solidline b in FIG. 5.

The HDR transmission video data from the branch level B to the referencelevel G is converted so as to match a value of the conversion data inaccordance with the SDR photoelectric conversion characteristic in thedynamic range inverse conversion performed by the dynamic range inverseconversion unit 208. In this case, the reference level G is made tomatch the relative maximum level M which is the SDR maximum level. Notethat the input data less than the branch level B becomes output data asit is.

Here, the conversion information is given by the conversion table or theconversion coefficient as described above. In a case where theconversion information is given by the conversion table, the dynamicrange inverse conversion unit 208 performs the conversion by referringto this conversion table. On the other hand, in a case where theconversion information is given by the conversion coefficient, thedynamic range inverse conversion unit 208 performs the conversion bymaking a calculation using this conversion coefficient. For example, ina case where the conversion coefficient is C, the conversion isperformed using the following equation (2) with respect to the inputdata from the branch level B to the reference level G.

Output data=branch level B+(input data−branch level B)*1/C   (2)

Next, the details of the dynamic range inverse conversion will bedescribed with reference to FIG. 16. This is a case where original videodata of the current stream is HDR video data. In this case, the inputlevel to the HDR EOTF curve is converted into the input level to the SDREOTF curve by the dynamic range inverse conversion unit 208. In FIG. 16,parts corresponding to those in FIG. 15 are denoted by the same signs.Note that P1′ indicates an output luminance level corresponding to apredetermined level H lower than the reference level G.

In this case, in the dynamic range inverse conversion performed by thedynamic range inverse conversion unit 208, the input data up to thepredetermined level H lower than the reference level G is converted in asimilar manner to the above-described dynamic range inverse conversionwhich is the case where the original video data is SDR video data. Then,level conversion is performed on the input data from the level H to thelevel M on the basis of a tone mapping characteristic TM, through whichoutput data is obtained. The tone mapping characteristic TM is indicatedby an alternate long and short dashed line. In this case, the level H isconverted into the level H″, the reference level G is converted into thelevel G″, and the level M is the level M as it is, for example.

By performing the level conversion on the input data from the level H tothe level M on the basis of the tone mapping characteristic TM in thismanner, it is possible to reduce deterioration in image quality due tothe level saturation from the reference level G to the relative maximumlevel M.

The SDR electro-optical conversion unit 209 obtains display video dataVsd for displaying an SDR image by applying the SDR electro-opticalconversion characteristic to the SDR transmission video data obtained bythe dynamic range inverse conversion unit 208.

The operation of the service receiver 200 illustrated in FIG. 14 will bebriefly described. In the reception unit 202, an MP4 distribution streamSTM transmitted from the service transmission system 100 on a broadcastwave or in a network packet is received. This distribution stream STM issupplied to the container decoder 203. In the container decoder 203, avideo stream VS is extracted from the MP4. In the container decoder 203,furthermore, meta-information is extracted from the MP4, and transmittedto the control unit 201. The control unit 201 recognizes from thismeta-information that the stream is an HDR stream, as well as HDRelectro-optical conversion characteristic information, original videodata information, and the like.

The video stream VS extracted in the container decoder 203 is suppliedto the video decoder 204. In the video decoder 204, decoding processingis performed on the video stream VS, through which HDR transmissionvideo data V1 is obtained. In the video decoder 204, furthermore,parameter sets and an SEI message inserted into each access unitconstituting the video stream VS are extracted and transmitted to thecontrol unit 201.

The control unit 201 recognizes from the meta-information in a VUI areaof an SPS NAL unit that the stream is an HDR stream, as well as the HDRelectro-optical conversion characteristic information, and the like.Furthermore, dynamic range conversion information (conversion table,conversion coefficient) is recognized from a dynamic range conversionSEI message.

In the YCbCr/RGB conversion unit 205, the HDR transmission video data V1obtained in the video decoder 204 is converted from the CbCr (luminanceand chrominance) domain to the RGB domain. In a case where a displaymonitor supports HDR, the HDR transmission video data V1 converted intothe RGB domain is supplied to the HDR electro-optical conversion unit207 through the changeover switch 206.

In the HDR photoelectric conversion unit 207, the HDR electro-opticalconversion characteristic is applied to the HDR transmission video dataV1, through which display video data Vhd for displaying an HDR image isobtained. After display mapping processing is appropriately performed onthis display video data Vhd according to the display capability of thedisplay monitor, the display video data Vhd is supplied to the displaymonitor and the HDR image is displayed.

On the other hand, in a case where the display monitor supports SDR, theHDR transmission video data V1 converted into the RGB domain is suppliedto the dynamic range inverse conversion unit 208 through the changeoverswitch 206. The dynamic range conversion information (conversion table,conversion coefficient) is given to the dynamic range inverse conversionunit 208 by the control unit 201 In the dynamic range inverse conversionunit 208, dynamic range inverse conversion is performed on the HDRtransmission video data V1 on the basis of this conversion information,which is then converted into SDR transmission video data (see FIG. 15).Note that these color space domains are not limited to the RGB domain,and the luminance and chrominance domain is not limited to YCbCr.

This SDR transmission video data is supplied to the SDR electro-opticalconversion unit 209. In the SDR electro-optical conversion unit 209, theSDR electro-optical conversion characteristic is applied to the SDRtransmission video data, through which display video data Vsd fordisplaying an SDR image is obtained. After display mapping processing isappropriately performed on this display video data Vsd according to thedisplay capability of the display monitor, the display video data Vsd issupplied to the display monitor and the SDR image is displayed.

As described above, the SDR transmission video data which is the videomaterial produced as the video by the SDR OETF is transmitted afterbeing converted into the HDR transmission video data in the transmissionand reception system 10 illustrated in FIG. 3. Even when transmittingthe SDR video data, therefore, the reception side can perform similarprocessing to that in the transmission of the HDR video data. This makesit possible to simplify the reception-side processing which is performedin a case where transmission of the SDR video data and transmission ofthe HDR video data are alternately performed.

Furthermore, the dynamic range conversion information (conversion cable,conversion coefficient) is inserted into the video stream or thecontainer and transmitted in the transmission and reception system 10illustrated in FIG. 3. The dynamic range conversion information is forconverting the value of the conversion data in accordance with the SDRphotoelectric conversion characteristic into the value of the conversiondata in accordance with the HDR photoelectric conversion characteristic.The use of this conversion information, therefore, allows the receptionside to easily perform processing for converting the HDR transmissionvideo data into the SDR transmission video data and displaying the SDRimage.

2. Modification

Note that although not described above, in a case where values of“reference_level”, “branch_level”, and “level_conversion_ratio” that arepremised in the present technology are fixedly defined on thetransmission and reception sides, the service receiver 200 may be areceiver that has a function of performing a similar level conversionwith respect to received data in a distribution where the valuesdescribed above are guaranteed in advance even if these elements are nottransmitted.

Furthermore, the embodiment described above illustrates an example inwhich the container is MP4. However, the present technology is notlimited to MP4, and may also be similarly applicable to containers inany other formats such as MPEG-2 TS and MMT.

For example, in the case of MPEG-2 TS, a transport stream TS including avideo stream VS is generated in the container encoder 109 of the servicetransmission system 100 illustrated in FIG. 4.

At this time, meta-information indicating, for example, that the streamis an HDR stream is inserted into the transport stream TS in thecontainer encoder 109. For example, the container encoder 109 inserts adynamic range conversion descriptor (Dynamic_range_conversiondescriptor) under a program map table (Program Map Table (PMT)).

FIG. 17 illustrates an exemplary structure (Syntax) of the dynamic rangeconversion descriptor. FIG. 18 illustrates the contents (Semantics) ofthe main information in the exemplary structure. An 8-bit field of“descriptor_tag” indicates a descriptor type. Indicated here is a highdynamic range descriptor. An 8-bit field of “descriptor_length”indicates the length (size) of the descriptor, which indicates thenumber of subsequent bytes as the length of the descriptor.

An 8-bit field of “ highdynamicrange” indicates whether the currentstream is an HDR stream. “1” indicates an HDR stream, and “0” indicatesan SDR stream. An 8-bit field of “transferfunction” indicates anelectro-optical conversion characteristic (EOTF characteristic). Forexample, “1” indicates “BT.709-5 Transfer Function”, “14” indicates “10bit BT.2020 Transfer Function”, and “16” indicates “SMPTE 2084 TransferFunction”.

An 8-bit field of “xycolourprimaries” indicates a color space. Forexample, “1” indicates “BT.709-5”, “9” indicates “BT.2020”, and “10”indicates “SMPTE 428 or XYZ”. An 8-bit field of “matrixcoefficients”indicates a color matrix coefficient. For example, “1” indicates“BT.709-5”, “9” indicates “BT.2020 non-constant lumiinance”, and “11”indicates “SMPTE 2085 or Y′D′zD′x″.

An 8-bit field of “referencelevel” indicates the reference level G (seeFIG. 5). In this case, a value specified with a value of 0 to 100 in arelative range normalized to “1” at maximum is described as thereference level G. A value obtained by dividing this value by 100 isrecognized as a relative reference level on the reception side. Thisrelative reference level constitutes a conversion coefficient asconversion information for the dynamic range conversion.

An 8-bit field of “branchlevel” indicates the branch level B (see FIG.5). In this case, a value specified with a value of 0 to 100 in arelative range normalized to “1” at maximum is described as the branchlevel B. A value obtained by dividing this value by 100 is recognized asa branch level on the reception side.

A 4-bit field of “streamdependency” indicates whether the current streamis an independent stream. For example, “0” indicates an independentstream, and “1” indicates a dependent stream. A 4-bit field of“originaldynamicrange” indicates whether original video data of thecurrent stream is SDR video data. For example, “0” indicates SDR videodata, and “1” indicates HDR video data.

FIG. 19 illustrates an exemplary configuration of the transport streamTS. In this exemplary configuration, there exists a PES packet “videoPES1” of a video stream identified by PID1. Meta-information is insertedinto a VUI area of an SPS of an access unit. The meta-informationindicates that the stream is an HDR stream, as well as an HDRelectro-optical conversion characteristic, and the like. Furthermore, adynamic range conversion SEI message is inserted into the access unit.Dynamic range conversion information is described in the dynamic rangeconversion SEI message.

Furthermore, the transport stream TS includes a program map table (PMT)as program specific information (PSI). The PSI is information describingwhich program each elementary stream included in the transport streambelongs to. In the PMT, there exists a program loop (Program loop) thatdescribes information related to the entire program.

In the PMT, there exists an elementary stream loop having informationrelated to each elementary stream. In this exemplary configuration,there exists a video elementary stream loop (video ES loop)corresponding to the video stream. Not only is information such as astream type and a packet identifier (PID) arranged corresponding to thevideo stream, but also a descriptor describing information related tothe video stream is arranged in the video elementary stream loop (videoES loop).

A value of “Stream_type” of this video stream is set to a valueindicating, for example, an HEVC video stream. The PID informationindicates PID1 added to a PES packet “video PES” of the video stream. Adynamic range conversion descriptor is inserted as one of thedescriptors.

Furthermore, the present technology can also have a configuration asfollows.

(1) A transmission apparatus including:

a dynamic range conversion unit configured to obtain high dynamic rangetransmission video data by performing dynamic range conversion onstandard dynamic range transmission video data on the basis ofconversion information for converting a value of conversion data inaccordance with a standard dynamic range photoelectric conversioncharacteristic into a value of conversion data in accordance with a highdynamic range photoelectric conversion characteristic, the standarddynamic range transmission video data being obtained by performing, onstandard dynamic range video data, photoelectric conversion inaccordance with the standard dynamic range photoelectric conversioncharacteristic;

an encoding unit configured to obtain a video stream by performingencoding processing on the high dynamic range transmission video data;and

a transmission unit configured to transmit a container having apredetermined format and including the video stream.

(2) The transmission apparatus according to (1) above, furtherincluding:

an information insertion unit configured to insert the conversioninformation into the video stream and/or the container.

(3) The transmission apparatus according to (2) above,

in which the information insertion unit further inserts, into thecontainer, information indicating that the video stream supports a highdynamic range.

(4) The transmission apparatus according to (2) or (3) above,

in which the information insertion unit further inserts, into thecontainer, information indicating a high dynamic range electro-opticalconversion characteristic corresponding to the high dynamic rangephotoelectric conversion characteristic.

(5) The transmission apparatus according to any one of (2) to (4) above,

in which the information insertion unit further inserts, into thecontainer, information indicating that original video data is thestandard dynamic range video data.

(6) The transmission apparatus according to any one of (1) to (5) above,

in which the conversion information is of a conversion coefficient.

(7) The transmission apparatus according to any one of (1) to (5) above,

in which the conversion information is of a conversion table.

(8) A transmission method including:

a dynamic range conversion step of obtaining high dynamic rangetransmission video data by performing dynamic range conversion onstandard dynamic range transmission video data on the basis ofconversion information for converting a value of conversion data inaccordance with a standard dynamic range photoelectric conversioncharacteristic into a value of conversion data in accordance with a highdynamic range photoelectric conversion characteristic, the standarddynamic range transmission video data being obtained by performing, onstandard dynamic range video data, photoelectric conversion inaccordance with the standard dynamic range photoelectric conversioncharacteristic;

an encoding step of obtaining a video stream by performing encodingprocessing on the high dynamic range transmission video data; and

a transmission step of transmitting, by a transmission unit, a containerhaving a predetermined format and including the video stream.

(9) A reception apparatus including:

a reception unit configured to receive a container having apredetermined format and including a video stream obtained by encodinghigh dynamic range transmission video data;

a decoding unit configured to obtain the high dynamic range transmissionvideo data by performing decoding processing on the video stream;

a dynamic range conversion unit configured to obtain standard dynamicrange transmission video data by performing dynamic range conversion onthe high dynamic range transmission video data obtained by the decodingunit; and

an electro-optical conversion unit configured to obtain display standarddynamic range video data by performing, on the standard dynamic rangetransmission video data, electro-optical conversion in accordance with astandard dynamic range electro-optical conversion characteristic, thestandard dynamic range transmission video data being obtained by thedynamic range conversion unit.

(10) The reception apparatus according to (9) above,

in which the high dynamic range transmission video data obtained by thedecoding unit is obtained by performing dynamic range conversionprocessing on the standard dynamic range transmission video data on thebasis of conversion information for converting a value of conversiondata in accordance with a standard dynamic range photoelectricconversion characteristic into a value of conversion data in accordancewith a high dynamic range photoelectric conversion characteristic, thestandard dynamic range transmission video data being obtained byperforming, on standard dynamic range video data, photoelectricconversion in accordance with the standard dynamic range photoelectricconversion characteristic.

(11) The reception apparatus according to (9) or (10) above,

in which conversion information is inserted into the video stream and/orthe container,

a conversion information extraction unit configured to extract theconversion information from the video stream and/or the container isfurther included, and

the dynamic range conversion unit performs the dynamic range conversionon the basis of the conversion information extracted by the conversioninformation extraction unit.

(12) A reception method including:

a reception step of receiving, by a reception unit, a container having apredetermined format and including a video stream obtained by encodinghigh dynamic range transmission video data;

a decoding step of obtaining the high dynamic range transmission videodata by performing decoding processing on the video stream;

a dynamic range conversion step of obtaining standard dynamic rangetransmission video data by performing dynamic range conversion on thehigh dynamic range transmission video data obtained by the decodingstep; and

an electro-optical conversion step of obtaining display standard dynamicrange video data by performing, on the standard dynamic rangetransmission video data, electro-optical conversion in accordance with astandard dynamic range electro-optical conversion characteristic, thestandard dynamic range transmission video data being obtained by thedynamic range conversion step.

A main feature of the present technology is to simplify reception-sideprocessing performed in a case where transmission of SDR video data andtransmission of HDR video data coexist in a time sequence. This isachieved by converting SDR transmission video data, which is a videomaterial produced as a video by an SDR OETF, into HDR transmission videodata and transmitting the HDR transmission video data (see FIGS. 4 and5).

REFERENCE SIGNS LIST

-   10 Transmission and reception system-   30A, 30B MPEG-DASH-based stream distribution system-   31 DASH stream file server-   32 DASH MPD server-   33, 33-1 to 33-N Service receiver-   34 CDN-   35, 35-1 to 35-M Service receiver-   Broadcast transmission system-   100 Service transmission system-   101 Control unit-   103 HDR photoelectric conversion unit-   104 SDR photoelectric conversion unit-   105 Dynamic range conversion unit-   106 Changeover switch-   107 RGB/YCbCr conversion unit-   108 Video encoder-   109 Container encoder-   110 Transmission unit-   200 Service receiver-   201 Control unit-   202 Reception unit-   203 Container decoder-   204 Video decoder-   205 YCbCr/RGB conversion unit-   206 Changeover switch-   207 HDR electro-optical conversion unit-   208 Dynamic range inverse conversion unit-   209 SDR electro-optical conversion unit

1. (canceled)
 2. A transmission apparatus comprising: processingcircuitry configured to obtain first dynamic range transmission videodata by applying a first photoelectric conversion characteristic tofirst dynamic range video data, convert the first dynamic rangetransmission video data to second dynamic range transmission video databased on conversion information for converting a value of conversiondata in accordance with the first photoelectric conversioncharacteristic into a value of conversion data in accordance with asecond photoelectric conversion characteristic, obtain a video stream byperforming encoding processing on the converted second dynamic rangetransmission video data, and insert the conversion information into thevideo stream; and a transmitter configured to transmit the video stream.3. The transmission apparatus according to claim 2, wherein a firstdynamic range of the first dynamic range transmission video data is astandard dynamic range, and a second dynamic range of the second dynamicrange transmission video data is a high dynamic range.
 4. Thetransmission apparatus according to claim 2, wherein the processingcircuitry is further configured to: obtain the second dynamic rangetransmission video data by converting from a color space to a luminanceand chrominance domain.
 5. The transmission apparatus according to claim2, wherein the transmitter is further configured to: transmit metadataincluding information indicating a dynamic range of the video stream. 6.The transmission apparatus according to claim 2, wherein the transmitteris further configured to: transmit metadata including informationindicating an electro-optical conversion characteristic corresponding tothe second photoelectric conversion characteristic.
 7. The transmissionapparatus according to claim 6, wherein the metadata further includesinformation indicating color primaries for the video stream.
 8. Thetransmission apparatus according to claim 7, wherein the metadatafurther includes information indicating color matrix coefficient for thevideo stream.
 9. The transmission apparatus according to claim 2,wherein the transmitter is further configured to: transmit metadataincluding information indicating an original dynamic range of the videostream.
 10. The transmission apparatus according to claim 2, wherein theconversion information is a conversion coefficient.
 11. The transmissionapparatus according to claim 2, wherein the conversion information is aconversion table.
 12. A transmission method comprising: obtaining firstdynamic range transmission video data by applying a first photoelectricconversion characteristic to first dynamic range video data; convertingthe first dynamic range transmission video data to second dynamic rangetransmission video data based on conversion information for converting avalue of conversion data in accordance with the first photoelectricconversion characteristic into a value of conversion data in accordancewith a second photoelectric conversion characteristic; obtaining a videostream by performing encoding processing on the converted secondtransmission video data; inserting the conversion information into thevideo stream; and transmitting via a transmitter the video stream.
 13. Areception apparatus comprising: a receiver configured to receive a videostream of encoded second dynamic range transmission video data; andprocessing circuitry configured to, obtain the second dynamic rangetransmission video data by performing decoding processing on the videostream, obtain first dynamic range transmission video data by performingdynamic range conversion on the second dynamic range transmission videodata, and display first dynamic range video data by performing, on thefirst dynamic range transmission video data, electro-optical conversionin accordance with a first electro-optical conversion characteristic.14. The reception apparatus according to claim 13, wherein the seconddynamic range transmission video data is obtained by performing dynamicrange conversion processing on the first dynamic range transmissionvideo data based on conversion information for converting a value ofconversion data in accordance with a first photoelectric conversioncharacteristic into a value of conversion data in accordance with asecond photoelectric conversion characteristic, the first dynamic rangetransmission video data being obtained by performing, on the firstdynamic range video data, photoelectric conversion in accordance withthe first dynamic range photoelectric conversion characteristic.
 15. Thereception apparatus according to claim 14, wherein the receiver isfurther configured to receive metadata including information indicatingan electro-optical conversion characteristic corresponding to the secondphotoelectric conversion characteristic.
 16. The reception apparatusaccording to claim 14, wherein conversion information is inserted intothe video stream, the processing circuitry is further configured toextract the conversion information from the video stream, and performthe dynamic range conversion based on the conversion information. 17.The reception apparatus according to claim 13, wherein a first dynamicrange of the first dynamic range transmission video data is a standarddynamic range and a second dynamic range of the second dynamic rangetransmission video data is a high dynamic range.
 18. The receptionapparatus according to claim 14, wherein the second dynamic rangetransmission video data is obtained by converting from a color space toa luminance and chrominance domain.
 19. The reception apparatusaccording to claim 13, wherein the receiver is further configured toreceive metadata including information indicating a dynamic range of thevideo stream.
 20. The reception apparatus according to claim 19, whereinthe metadata further includes information indicating color primaries forthe video stream.
 21. The reception apparatus according to claim 20,wherein the metadata further includes information indicating colormatrix coefficient for the video stream.
 22. The reception apparatusaccording to claim 13, wherein the receiver is further configured toreceive metadata including information indicating that original dynamicrange of the video stream.
 23. A reception method comprising: receiving,by a receiver, a video stream of encoded second dynamic rangetransmission video data; obtaining the second dynamic range transmissionvideo data by performing decoding processing on the video stream;obtaining first dynamic range transmission video data by performingdynamic range conversion on the second dynamic range transmission videodata; and displaying first dynamic range video data by performing, onthe first dynamic range transmission video data, electro-opticalconversion in accordance with a first electro-optical conversioncharacteristic.